Film heater and vaporizer



March 1931; c. w. STRATFORD FILM HEATER AND VAPORIZER Filed Feb. a, 19282 Sheets-Sheet 1 T202? (24 AW B 2%44/ 5W ATTORNEY FILM HEATER ANDVAPORIZER Filed Feb. 8, 1928 2 Sheets-Sheet 2 &

i INVENTOR gar/a5 fi akai M122 5% I 117%5115Y Patented Mar. 10, 193,1 7

UNITEDSTATES" PATENT OFFICE GEABLES WALGO'I'T s'rzaa'rroan, oronxnanngohmonm FILM HEATER AND VAPORIZEB Application filed February-8,1928. Serial 1T0. 252,757.

This invention relates to improvements in' forming a closed annularcontaining space- I for the fluids, and a heat supply, or means forheating the interior or inner .tube, the fluid being introduced andimpinged heated surface of the inner tube, whereby a circulation orrapid movement of the film of fluid is produced, aiding materiallyinremoving the heat, thereby transmitting the heat more rapidly to thefluid; {to provide also an apparatus whereby the heat exchange betweenthe fluid undergoing heating and the combustion gases, is substantiallyinstantaneous; and in general, to provide a method and apparatushereinafter described. Figure 1 is a diagrammatic side elevational 'viewof the heater with parts broken away.

1 Figure 2 is a view taken along the line A-A in Fig-u Figure 3 1s asectional side view of a preheating apparatus to be used in connectionwith the heater. I

Figure 4 is 'a top section of the preheater furnace,'shown-in'Figure 3.

' Figure 5' is an enlarged detail of the connections to the annularspace between the telescopic tubes.

Figure 6 is a diagrammatic side elevational.

40 heater connected into a system for heating oil.

Referring to the drawings, the heater. consists of two cylindricalvessels 1 and 2', hav

ing diameters slightly different and placed one Within the other to forman annular space 3,. therebetween. The'outer sheet or tube has formedtherein, protrusions 1,

Y which serve as connections to the discharge leads 6 the inletleads 5being connected directlyto the outer shell '2. The inlet leads againsttheof the discharge pipes 5 and 6 are arranged are connected toinlet-laterals 7 running longitudinallyof the cylindrical vessels 1 and2, and hesel terals 7, in turn, have connection, through pipes 8, withthe ring headers 9.. Connected to the ring headers, is a distributinhea'der10 supplied with fluid through the ischarge line 11 of the pump12.' In brief, then, the supply distributing circuit consists of a pump12, driven by a motor 13, supplying fluid through the line 11, to theheader-10, thence to the distributing ring headers 9 from which thefluid is supplied .to the laterals? through the connections 8 andfinally through the jets 5'to the annular space between the inner andouter cylindrical vessels. I

Similarly, there is a discharge circuit, consistin of withdrawal leads6, connecting into t e laterals 14, which, in turn, have connection withthe ring headers 15. These ring headers have communication through thepipes 16, with the header 17 frdm which a, single discharge line 18,furnishes a means for withdrawin or removing thefluid after heating,from t e system.

The thickness .of the annular space-3, between the telescopictubes mayvary accordin to the character of the material which is bemg heatedandits susceptibility to the transmission of heat. At the extremities ofthe inlet leads 5, there are preferably positione'd nozzles such as thatdescribed in connection with the circulatorysystem of my Patent No.1,613,298, issued January 4th,

1927. These nozzles spread the liquidin a thin film upon the innercurved heated surface and produce a rapidly moving layer of oil in alldirections, over the inner heated surface from the separate-nozzles. Theinlets 00 and positioned over the surfaceof the outeiJ shell so as toproduce arelatively continuous. sheet of rapidly moving fluid over theinner heated curved surface. I

To heat the interiorof the vessel at one end of the inner tube is aburner such as that diagrammatically shown at 19. The 1 combustion gasesfrom the burner travel longitudinally of the inner tube and areexhaustedor discharged through a duct or flue. 20 which I preheated fluid is"preferably heavily insulated-as shown at 21. This duct is connected upwith a flue dis charge pipe which leads to a chimney orstack, not shown.Within the enlarged duct 7 29, is heat exchanging surface-in the form ofa sinuous coil or pipe 22.

In operation, fluid is supplied from any,

convenient source through pump- 12 and the p1pe 11, where it ispreheated by the combustion gases discharged from the exhaust end of thetube 1, shownin Figures 4 and 6.' Instead of passing first through apreheating section such as the pipes 22, the fluid may be charged directto the heater through the 15 pump 12 from any suitable source, as'shownin Fig. 1. ere,a preheater is used, the

is discharged then through the hne 11, into the header "10,'thencethrough the leads 8 to the laterals 7, by

6 means of which it is distributed to the inlet pipes 5. At theextremities of the inlet pipes or where the fluid is discharged into theannular space between the cylinders 1 and 2, there are distributingnozzles which impinge the fluid traveling at high velocity, onto theinner curved heated surface, this inner'cylmder being highly heated,immediately or substantially instantaneously, transmits its heat to thefilm offluid traveling rapidly over so its surface. The fluid is thendischarged at high velocity through the pipes6, in the laterals 14, andheaders 15, to the leads 16- and discharge headers 17 andpipe 18,throughwhich it is delivered to separating and fractionating apparatusesof any suitable type, accordingto the fluid which is being heated.

The methodand apparatus isadapted to use in the heating of petroleumhydrocar- 40 bons, coal tar distillates, in the distillation of water 1nsteam boiler practice, and for innumerable other uses in' connectionwith the y heating'or distillation of liquids or fluid ma terials. It ispartiularly useful in the dis- I tillation of lubricating oils whererapid heat exchange and distillation aredesired without decompositlon,and in this connection the. heater lends itself to use in vacuumapparatus. Y i

to The rapidity of heat exchange and the efli ciency of themethod bywhich the heat of the combustion; gases is taken up by'the rap' idlymoving film, permit the burning of the fuel at the bestpossible oroptimum condi- 'tions of combustion. The separate distributing circuitintroduces the uid" discharged by impingement onto the heatedcurvedsurface, at decreasing velocities which promotes; equalizationofthe fluid distribution at the 0 pointwof impingement.

The apparatusshown in Figurefi, discloses the use'of the'llieater asapplied'fito an oil distilling system maintained either underatmospheric orsubstantially atmospheric con-. 5 ditions-of pressureor'flunder high vacuum.

The heated fluid is discharged from the heater through the pipe 18 andpasses through an adjustable valve 25, interposed in the exthereof, acentrifugal pump rotor diagrammatically shown at 30. The discharge fromthe pump is designated in the drawings as 31 and communicates with theline 11 by means of which the oil, unvaporized in the separator 26,is-returned to the heater. A

secondary withdrawal line 32, connected into the line 31, serves toremove portions of the liquid bottoms from the system. 1 Thislatter'line iscontrolled by a diaphragm operated valve 33, automaticallymanipulated by meansof the liquid level control device 34,

aifixed to the side of the separator. A takeoli vapor' line 35 isconnected into the inner cylinder 28 and communicates with thefractionating' tower 36 into which the vapors evolved from the liquid inthe separator are led over, to the-fractionating tower, where the aresubjected to refluxing action. Contro led fractionation is'p'ractised inthe tower 36 and overheadvaporis taken ofi through the line 37 anddirected to the' condenser 38,

passing thence through the line 39, in the form of distillate, to thegas separator 40.

Liquid accumulating in the bottom of the fractionating tower, is takenoff by thedraw off line 41,,regulated by the valve 42, eitherautomatically or manua y. When the system is operated under vac uum, abarometric condenser maybe interposed in-the line 39 and the vacuumpumps. 43 and 44put into operation.

When vacuum is not being used, the liquid andvapor drawofi lines 45 and46, may be used. A steam line is connected into the bottom of the vaporliquid separator 26. As suggested, the heated fluid discharged from thefilm evaporator or heater, passes through the line 18 and is dischargedthrough" the the liquid clinging to-the inner surface due to thecentrifugal force of the vapor accumu lation in the vortex or in the.central portion of the chamber:" This vapor rises through the open-endedpipe 28 passes out throughthe vapor pipe 35, into the fraction- ,atingordephlegmating column 36. In this latter column, there is refluxed, thestill vaporized portion passing overhead through.

- lating as the line 37 to the condenser 38 and accumudistillate in thegas separator 40. The liquid, unvaporiz'ed in the vapor liquidseparator, accumulates and is discharged by the pump rotor through theline 31, back to the heater through lines 24 and 11. Simultaneously,there iswithdrawn, a regulated portion ofthe tar bottoms, through theline 32, the amount of withdrawal being controlled by the liquid leveldevice 34. i

The injection, of steamthrough the line 47, accelerates the evolution ofvapors in the separator and improves the character of the finaldistillation, preventing to a great extent, decomposition.

equipment in which oil may be heated to de sired terminal temperatureswithin an extremely short period of time. The ideal system would be onein which the temperature of distillation could be reachedin a chargingrate to this heater does not period of a few seconds, vaporization thenaccomplished in a zone of lowest possible hydrocarbon pressures, to keepdown terminal temperature, and a system in which the distillates arerapidly cooled after fractionation or separation.

The heater described, comprises a firing tube against the outer surfaceof which the oil to be heated is impinged. Surrounding the firing tubeis placed a concentric collector tube encloslng a thin annular space,

of small total volume for the flow of oil, manifolding for the uniformdistribution of oil, from the discharge of the circulating pump, to thenozzles, is attached tothe outer shell as is also themanifoldingfor'receiving the heated oil as it is forced fromthe annularspace through slotsand passes directly to the vaporizer. The circulatingpump, being incorp orated in the vaporizer, receives the separated oildischarging a portion from the system and sending theremainder-- backthrough the heater withthe fresh feed. Energy put into the circulatingpump is usefully expended in imparting desired high velocity to thesheet flow of oil Allof'this surface over the heating surface. sees thefire ailiti'aiisfers heat at a uniformrate. The firing tube can beeasily withdrawn for inspection. It is evident that influvolume capacitydivided factor that is many times too ence velocity of, oil over. theheating surface though it does change the time factor.

' Examining the principal causes of failure of heat absorption byliquids we find nothing that cannot be easily corrected. The entiretransfer surface should be swept by a continuous sheet of liquid movingat high ve' locity in most complete and intimate contact with it. Thisflood ofJiquid must be of sufficient quantity to furnish an adequatemedium for absorbing all the heat transmitted. Immediately after contactwith the heating sheet the oil should be allowed to freely evaporate.Liquid flow at high velocity assures perfect cleanliness on the oil sideof the sheet, guarantees lowest oil film temperatures, and prevents theaccumulation of silt, carbon or salt films having high heat insulatingproperties.

-capac1ty of oil vapors or. of these vapors mixed with atomized oil ismany times lower than that of liquid oil. From this fact it follows thata heating surface canOnly be suflicientl protected; from failure by thesweep of iquid oil, when this surface, on the fire side, is directlyexposed to absorption of radiant heat at high temperature levels and athigh .spe'cific rates. The present system fulfills all requirementsof-highest transfer rates.

I claim as my invention:

1. An apparatus for heatingfluids comprising telescopic plain surfacedtubes ,forming a closed annular containing space for. the

fluids, means for heating the interior of they inner tube, and means fordischarging by vertical impingement against the exterior of the innertube the sheet flow in predetermined circulation areas at the heatedsurface.

2. An apparatus for heating fluids comprising telescopic tubes forming aclosed annular containing space for tlfe fluids, means for heating theinterior of the inner tube, a plurality of jets for discharging byimpingement against the exterior of the inner tube fluid to be heated toproduce a The heat absorbing v the fluid to be heated to produce acontinuous sheet flow' over defined circulation areas at the heatedsurface, drawal'lines from said containing annular sp i the steps ofimpinging the fluid upon a tube heated from within. in a plurality ofunbroken liquid jets projected vertically over .pre-

determined circulation areas to produce a sheet flow ofrela'tivelyiuniform depth adj aand supply lines and withace. i 3. Amethodof heating fluids comprising cent the curved heated surface, andheating the shallow film of fluid formed: bythe im-" pingement thereofagainst the tube.

- 4. A method of'heating fluids comprising the steps of impinging thefluid against the exterior of a heated tube through, a of liquid'jetsheated surface, said jets plurality projected vertically onto thepositioned at prede- 4 yroaevc I termined points on the curved surfaceto produce a continuous sheet flow of uniform distribution, and removingthe fluid at a plurality of predetermined points arranged to 5 maintaina series of defined circulation areas upon the heated tube.

5. An apparatus for heating fluids comprising, spaced telescopic tubesforming a closed annular heating surface for fluids to be heated, meansfor heating the interior of .the inner tube, means in close proximity tothe heated surface for dischargin by impingement fluid againstthe curvedsurface thereof, said means positioned at a plurality v of points andarranged to create an equalization of fluid distribution, and withdrawalmeans for removing the heated fluid'at'a plurality of points arranged tomaintain defined circulation areas of the sheet flow produced by thetravel of the fluid from the impingement means to thewithdrawal means.

6.- An apparatusfor heating fluids comprising-spaced telescopictubesforming an enclosed annular containing space for the l 2 5 fluidsbetween the tubes, means for heating the interior of the inner tube, aplurality of jets uniformly distributed onthe exterior of the outer tubeand adaptedto supply the liquid to be heated .by vertical impingementagainst the exterior of the inner tube to produce a continuous sheetflow thereover,'and withdrawal linesfrom the containing annular space. j'ZJAn apparatus for heating fluids comprising spacedtelescopic tubesforming a closed annular containing space between thetubes for thefluids, means for heatingthe interior of the inner tube, jets andwithdrawal lines uniformly distributed on the external '10 surface ofthe outer tube whereby the fluid is impinged simultaneously at aplurality of points against the inner tube, setting up a sheet flow overdefined circulation areas at the transfer surface. 8. An apparatus forheating fluids comprising spaced telescopic tubes forming a closedannular containing space for the fluids, means for heating theinteriorjof the inner-tube, inlet jets and discharge ports dis tributed.over the surface of the outer tube vwhereby the fluid to' be heated'iscirculatedin' a continuous sheet flow over definedoirculation areas,at the heatedsurface.

. CHARLES STRATFORD.

